﻿    	function block_viewport(xval) {
    	    xval = getBusyOverlay(xval, { color: 'white', opacity: 0.5, text: 'viewport: loading...', style: 'text-shadow: 0 0 3px black;font-weight:bold;font-size:12px;color:white' }, { color: '#000', size: 12, type: 'o' });
    	    if (xval) {
    	        var c = 0, t = 100;
    	        xval.ntime = window.setInterval(function() {
    	            xval.settext('viewport: loading...' + c + '%');
    	            c++;
    	            if (c > t) {
    	                window.clearInterval(xval.ntime);
    	                xval.remove();
    	            }
    	        }, 50);
    	    }
    	}

    	;